Magneto



G. H. DINGMAN Oct. 2, 195] MAGNETO 3 Sheets-Sheet 1 Original Filed May23, 1946 INVENTOR ATTORNEY Oct. 2, 1951 G. H. DINGMAN 2,569,461

MAGNETO Original Filed May 23, 1946 s Sheets- Sheet 2 INVENTOR ATTORNEY1951 G. H. DINGMAN 2,569,461

MAGNETO Original Filed May 23, 1946 3 Sheets-Sheet 5 7 f INVENTOR BUMQ.flau% AJ'TOBNEX Patented Oct. 2, 1951 UNITED STATES MAGNETO Originalapplication May 23, 1946, Serial No.

PATENT OFFICE 671,695. Divided and this application February 9, 1950,Serial No. 143,203

12 Claims. (Cl. 171-209) This invention relates to magnetos and moreparticularly to the mechanical construction thereof and the mountingthereof on an engine casing or the like.

This application is a division of applicants copending application Ser.No. 671,695 filed May 23, 1946, for Magneto.

One of the objects of the present invention is to provide a mounting forthe parts of a magneto adapted to make the assembly of parts easy andefiicient.

Another object of the invention is to provide novel means for mounting amagneto stator on an engine casing or the like whereby the magneto maybe readily installed or removed from the casing and whereby adjustmentof the magneto relative to the casing is greatly facilitated.

The above and further objects and novel features of the invention willmore fully appear from the following detailed description when the sameis read in connection with the accompanying drawings. It is to beexpressly understood, however, that the drawings are for the purpose ofillustration only and are not intended as a definition of the limits ofthe invention.

1 In the drawings, wherein like reference characters refer to like partsthroughout the several views,

Fig. 1 is a plan view of a flywheel or crankshaft type of magneto withthe cam and shaft, and the rotor omitted;

Fig. 2 is a sectional view of the magneto stator taken on the line 2-2of Fig. 1;

Fig. 3 is a bottom plan view of the structure shown in Fig. 1;

Fig. 4 is a section on the line 44 of Fig. 1;

Fig. 5 is a schematic detail plan view showing the cam and its operativerelation to the breaker points located at diametrically oppositepositions; I Fig. 6 is a bottom plan view of the rotor broken away toshow concealed parts;

Fig. 7 is a section of same on the line 1-1 of Fig. 6; and

Fig. 8 is a diagram of the circuits.

, Referring to the numerals of the drawings, and particularly to Fig. l,a magneto transformer is indicated by the numeral 10, its associatedcondenser by the numeral ll, its associated circuit breaker by thenumeral I2, and its stator pole shoes by the numerals l3, l3. Theseoperative parts of the magneto are duplicated, but the initialdescription will be limited to them since the operation of theduplicates is identical, occurring, in the construction shown, 180later.

The frame I4 of the magneto comprises a casting, which may be ofaluminum or any other satisfactory metal or material of sufficientstrength and the requisite conductivity, having coaxial annuli I5, 16 ofwhich the smaller has outer dimensions approximating the innerdimensions of the larger and is supported there.- from by integral flatposts [1, IT.

The smaller annulus 16 carries a metal arm [3 pivotally attached theretoby a screw I9 and having a slotted end 20 through which a set screw 2|passes, giving adjustability to the position of the arm and the breakerelements mounted thereupon. Two metal ears 22, 23 project upwardly fromthe body of the arm l8, the first of which serves as a support forbreaker point 24 and the second of which serves as a support for spring25 which carries on its end a T-shaped dielectric cam follower 26. Thecam follower rides upon the cam carried by the shaft and is 20 displacedby the lobe of the cam toward the spring breaker arm 21, which carriesat its end a breaker point 28 which is normally in contact with breakerpoint 24, acting under the impulse provided by the cam to break thecircuit through I the points in the manner which will be understood bypersons skilled in the art. The breaker arm 2! is electrically connectedto the terminal of a cable 30 of the condenser II and to the terminal ofa cable 31 that issues from the coil 10. The coil is grounded throughthe cable 32 affixed at its terminal to the screw 33 that attaches thesupporting arm 34 of the other breaker to the frame or support it. Thecondenser II is grounded and fastened to the frame by a strap 35 whichencircles it and has its ends affixed to the plate l5 by a screw 36.

A mounting for the coil II is provided. As will be understood by personsskilled in the art, the coil has three leads, one to the primary, one tothe secondary, and a joint lead to the ground. One of these leads isbrought out, in the coil being described, through the circular wall ofthe coil and poses a problem of protection which has been cared for in anovel manner. A depressed and apertured seat 31 is provided, thecurvature of which conforms to that of the coil. The depressed seat hastwo halves that are separated by an aperture or slot 38 that is seenfrom the bottom in Fig. 3. The shape of the seat provides end abutmentswhich act to retain the coil against endwise displacement. A hightension lead 39 projects from the wall of the coil and is received inthe aperture in the seat.

In order that the lead and the coil itself may be protected againstdamage from the metal of the frame, from vibration, and from shock, aprotective pad 40 is provided. That pad is preferably made from aflexible dielectric substance such as rubber having a fiat or curved bed41 that overlies the coil and conforms to the shape of the seat. Achannel-shaped, depressed portion 42, having width about equal to thewidth of the aperture in the seat and length and depth sufficient toenclose the lead 39 is provided. An

opening $3 is provided in the end of the channelshaped portion 42,beneath the plate l5 through which the high tension lead is passed.Thehole in the protective pad may be made to-conform snugly to the leadso that vibration of the lead will not harmfully affect the connectionto the coil.

The core of the coil is connected to the stator shoes of the magneto.Laminated stator shoes l3, 13' are bolted to the plate 15 byboltssuch-as in such position that the curved portions thereof are inoperative relationto the rotor of the magneto. Raised lands 5|, formedintegrallywith the plate i5, serve to support the stator shoes. Theshoes have fiat ends 52 adapted to receive the fiat sides 53-01 the coreof the coil l0. Sharp notches 55 are provided in the upper ends of thecore 54 androunded notches 56 are provided in the sides of the statorshoes. Spring clamps 51 having sharp ends 58 and rounded ends 59areadapted to clamp the ends of the core to the stator shoes in firmelectrical connection while at the-same time they maintain the coil inits seat in the plate IS. The rounded endsof the clamps are easilysprung into and out of position, but when in placeform a firm connectionthatdoes not become accidentally disengaged.

The apparatus hereinabove described forms an interdependent novelcombination with the casing 60 (Fig. 2) of the engine or other apparatusfrom which the drive shaft 6| (Fig. 4) projects. The machine or enginecasing 60 has an annular flat top or end 62 and a groove Min-the wallbeneath the top thereby forming'a pilot flange. The frame M isinternallyprovided with a groove or recess 64, the upper face or end wall 65 ofwhich serves as a shoulder to restupon or against the end or outerradial wallGZ of the pilot flange of the casing. The annular orcylindrical wall of groove 64 has-a diameter substantially equal to thatof the pilot flange of the casing 60-and has a depthsubstantially equalto the distance between the end 62 and groove 63, i. e. the width of thepilot flange as illustratedparticularly in Fig. 2. Bolts 66 are mountedin and project freely through the plate [5 and are screw threaded intoplate 67 which serves as a nut. Between the plate or nut 61 and the-bodyof plate I5 is an adjustable clamp Behaving circularly projecting springarms or fingers 69 of curvature substantially conforming to that ofgroove 64. The arms or fingers 59-have offset cam ends to yieldablyengage the inner radial surface of the pilot flange within groove 63.The body portions of the plates 68 have slotslfl, as shown in Fig. 3,which permit it to be adjusted to move spring fingers 69 radially intoand out of groove 63 for clamping engagement with the pilot flange ofcasing 50. Clamping plates 68 have outwardly bent tongues 68 at theupper and lower ends thereof, as viewed in Fig. 3, which project beyondthe periphery of nut plate 61 and are accessible for facilitating radialmovement of the clamping plate whenthe bolts 66 are not tightened. Asmany of these clamping plates may be provided as are-necessary. Oncethey words Close and Open in Fig. 5.

are adjusted to groove 63 in casing 50 and, hence, with relation to thepilot flange, they may be fixed into position by tightening the bolts66, the heads of which are accessible from the upper or outer surface ofplate [5.

The cam 10 is mounted on the endof the shaft 6|, which projects throughthe annular plate I! into operative relation to the circuit breakers.The single lobe of the cam is indicated by the This cam operates the twocircuit breaker riders 26 alternately 180 apartso that the spark plugsserved by the respective magneto units are fired alternately. Byemploying a cam of two lobes, the magneto can be made to fire the plugssimultaneously each 180 of arc.

The magneto rotor is seated upon the shaft BI beneath the cam and inoperative alignment with the stator shoes. The shaft 6| has a seat TIupon which the rotor rests. Both the cam and the rotor are keyed to theshaft.

In Fig. 7, which isa section on the line 1-4-01 Fig. 6, the numeral 12indicates generally the frame of the rotor, which may conveniently be analuminum casting having an annular plate 13 and a hub 14. The corepiecesare laminated and are riveted to the plate 13 by means ofbrass coverplate 15 and. rivets 16. Two magnets, 11 and 18, are arranged attoeachother, as indicated in Fig. 6, with their north poles in adjacentposition. The north poles of the magnets are seated in appropriategrooves inlaminated core piece or shoe 19 which is-riveted to the plates13 and T5. The other ends ofthe magnets are similarly seated in V-shapedcore piece 8!], mid-portions of which are cutout to provide three shoes.The'middle shoe is substantially inactive so that thereare provided bythis arrangement a single north andtwo'operative south poles, all ofwhich are located within an arc of This produces a complete reversal offlux in the coil core once in each revolution of the rotor.

A wiring diagram for single circuit is illustrated in Fig. 8, it beingunderstood that a similar wiring diagram would be provided for thesecond magneto circuit. No attempt has been made in this diagram to timethe cam with relation to the position of the magnets, the particu lararrangement being chosen for clarity of representation rather than foroperative accuracy. In this figure is shown the'rotor with the top plate15 removed and'the cam and breaker displaced to the extremity of thediagram. The ends of the primary and secondary of the coil are connectedto the circuit breaker l2- and to the condenser ll, both ofwhichare-grounded. The other end of the primary is connected to ground,and the other end of the secondary is-connected to a spark plug, whichis grounded on the other side of the gap. When the leading end of shoe80 becomes aligned with the 'second'stator shoe, the shoe i9 is alignedwith the first'stator shoe and flux passes through the core in onedirection. When the shoe 19 reaches the second stator shoe, thefollowing end of shoe 80 reaches the first stator shoe and direction ofthe flux through the core is reversed. The-cam isset on the shaft tomake the most-efficient use of-this arrangement. Adjustment can be-madeby pivoting the arms I8 to new positions. Additional adjustments can bemade by moving the frame [4 clockwise and counter-clockwise on thecasing 60.

A particular advantage of this invention is in the construction of thesupporting frame and in the means for adjustably supporting it upon thecasing of the machine.

Another advantage of the invention is in the novel means of mounting theseveral parts of the magneto upon each other and upon the frame.

Although only one embodiment of the present invention has herein beenillustrated and described, it is to be expressly understood that thesame is not limited thereto. Various changes may be made in the designand arrangement of the parts illustrated and in the materials usedwithout departing from the spirit and scope of the invention, as willnow be apparent to those skilled in the art. For a definition of thelimits of the invention, reference is had primarily to the appendedclaims.

What is claimed is:

1. A connection comprising an annular body having an annular groove inthe curved side beneath the end, a frame having a portion adapted torest upon the annular body, a plate attached to the frame in proximityto the annular body having circularly projecting arms with offset.cam-like ends adapted to enter said groove, and means to adjust saidplate and to fix it in adjusted position.

2. A stator for a magneto comprising a frame having an annular recessfor receiving a circular pilot flange on a support, said flange havinginner and outer radial surfaces, and means for securing said frameagainst axial movement relative to said flange and for frictionallyholding the same against relative angular movement, said means includinga plurality of plates having spring fingers extending therefrom forfrictional engagement with the inner radial surface of said flange andscrews and nuts clamping said plates to said frame.

3. Apparatus as defined in claim 2 wherein each screw extends freelythrough the frame and plate for threaded engagement with a nut.

4. Apparatus as defined in claim 3 wherein the heads of the screws areaccessible from the side of the frame opposite said recess.

5. Apparatus as defined in claim 2 wherein the screws extend freelythrough the frame and plates, the openings in said plates through whichthe screws extend being elongated to permit radial movement of theplates when the same are not clamped by said screws and nuts, wherebysaid spring fingers may be moved into and out of axial alignment withthe pliot flange on the support.

6. Apparatus as defined in claim 5 wherein each plate is secured by aplurality of screws which engage a single nut in the form of a platehaving a plurality of threaded openings therein.

7. Apparatus as defined in claim 5 wherein the end portions of saidspring fingers are constructed to engage the pilot flange during thetightening of the screws and nuts before the plates on which saidfingers are carried are drawn into face-to-face engagement with theframe.

8. A stator plate for a flywheel magneto, having a recess with acylindrical wall adapted to receive and closely fit the periphery of apilot flange on an engine crankcase and an end wall adapted to engage anouter end face of said pilot flange, a plurality of spring-fingercarrying members mounted on the inner face of the plate with the fingersadapted to engage the inner end face of said pilot flange to hold theplate against axial displacement and to frictionally hold the plate invarious positions of angular adjustment,

said members being mounted on the stator plate for movement radially ofsaid recess from positions in which their spring fingers projectinwardly beyond the cylindrical wall of said recess to positions inwhich the spring fingers lie wholly outside such wall, each said memberhaving a part extending therefrom and accessible for moving the memberradially from one of said positions to the other, and screws and nutsfor holding the members in the first-named radial positions, each screwpassing freely through the stator plate with its head engaging the outerface thereof and threading into its nut, each nut being operativelyengaged with its member to draw the same toward said plate, the head ofeach screw being accessible from the outer face of the stator plate.

9. A stator plate for a flywheel magneto, having a recess with acylindrical wall adapted to receive and closely fit the periphery of apilot flange on an engine crankcase and an end-wall adapted to engage anouter end face of said pilot flange, a plurality of spring-fingercarrying members mounted on the inner face of the plate with the fingersadapted to engage the inner end face of said pilot flange to hold theplate against axial displacement and to frictionally hold the plate invarious positions of angular adjustment, said members being mounted onthe stator plate for movement radially of said recess from positions inwhich their fingers project inwardly beyond the cylindrical wall of saidrecess to positions in which the fingers lie wholly outside such wall,each said member having a part extending therefrom and accessible formoving the member radially from one of said positions to the other, andscrews and nuts for drawing the members toward said plate to carry thefingers against the inner end face of the pilot flange, each screwpassing freely through the stator plate with its head ongaging the outerface thereof and threading into its nut, the nuts being operativelyengaged with the members to draw the same toward the plate and carry thefingers against said inner end face of the pilot flange when the screwsare tightened and thereby adjust the pressure of the fingers on saidinner end face.

10. A stator plate for a flywheel magneto, having a recess with acylindrical wall adapted to receive and closely fit the periphery of apilot flange on an engine crankcase and an end wall adapted to engage anouter end face of said pilot flange, a plurality of spring-fingercarrying members mounted on the inner face of the plate with the fingersadapted to engage the inner end face of said pilot flange to hold theplate against axial displacement and to frictionally hold the plate invarious positions of angular adjustment, said members being mounted onthe stator plate for movement radially of said recess from a position inwhich their fingers project inwardly beyond the cylindrical wall of saidrecess to a position in which the fingers lie wholly outside such wall,and screws and nuts for drawing the members toward said plate and thefingers against the inner end face of the pilot flange, each screwpassing freely through the stator plate with its head engaging the outerface thereof and threading into its nut, said nuts being operativelyengaged with their members to draw the latter toward the plate and thefingers against said inner end face of the pilot flange when the screwsare tightened and thereby adjust the pressure of the fingers on saidinner end face.

11. Apparatus as defined in claim 10 wherein the screws pass throughelongated slots in said spring-finger carrying members whereby saidmembers are guided in their radial movements.

12. A stator plate for a flywheel magnetahaving a recess with acylindrical wall adapted to receive and closely fit the periphery of apilot flange on an engine crankcase and anend wall adapted to engage anouter end face of said pilot flange, a plurality of spring-fingercarrying members mounted on the inner face of theplate withthe fingersadapted to engage the inner end face of said pilot flange to hold theplate-against axial displacement and to fricticnally hold the plate invarious positions ofangular adjustment, said members being mounted onthe stator plate for movement radially of said recess from positions inwhich their fingers project inwardly beyond the cylindrical wall of saidrecess to positions in which the fingers lie wholly outside such well,each m mber having a bent part engageacle with the pilot flange as afulcrunr. and screws and nuts for swinging said members about their 8fulcrums topress: the fingers against-the inner end face of the pilotflange, each screw paasinl freely through the stator plate with itshead: engaging; the' outer face thereof and threading into its nut,.each nut being operatively engaged with its member to move itsfinger-carrying end toward and against said inner end face of the pilotflange when its screw is tightened, whereby to adjust the pressure ofthe fingers on said inner end face.

GLEN H. DINGMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,113,147 Zahringer Oct. 6, 19141,610,033 Hawkins Jan. 4; 192'! 2,363,436 Pancoe Nov. 21. 19 2,487,095Brownlee Nov. 8, 1949

